FDA Fails to Fix the Fosamax Fracture Fuss

In recent years, reports have emerged linking long-time therapy with Fosamax (and other bisphosphonate drugs) with an increased risk of unusual femur fractures.  This type of drug is used to prevent or treat osteoporosis, and since their introduction in the 1990s it’s been generally considered that they should be taken by the patient indefinitely, in order to preserve bone structure.  In 2005, the FDA added a warning on bisphosphonates about osteonecrosis of the jaw, a rare disease in which the bone in the jaw dies; the risk for this rare effect appears now to be more prevalent after 4 years or more of use.  And in 2010, the FDA required manufacturers to add a warning about a small increased risk of atypical femur fractures.     

A joint FDA advisory committee was asked last week to discuss the risks associated with long-term use of bisphosphonates and whether a "drug holiday" would help prevent fractures in patients who take the drugs for more than three years.  The committee felt the FDA should limit the duration of bisphosphonate therapy for osteoporosis (voting 17 to 6), but they couldn’t agree on exactly how long the drug should be given.  Controlled trials usually provide data for only five years of treatment, and there’s no good evidence that bisphosphonates work better after they're used for longer, while there’s little evidence that long-term use causes harm.  To get good data, more studies are needed.

In the meantime we should remember that, at least in the first 5 years, bisphosphonates are highly effective at reducing the risk of osteoporotic fractures. They have been shown to reduce the risk of breaking a hip by 40% to 50% and of fracturing a vertebra by between 40% and 70%.  Set these number of effectiveness against the extraordinary few femur fractures and cases of ‘fossy-jaw’ reported, and there’s little doubt that these drugs must continue to be prescribed, where necessary. Let’s hope expert advice will emerge with specific proposals about the likely benefits (or disadvantages) of a “drug holiday” after 3 (or 4, or 5?) years.